Question 2007 Sante Fe, need to fit convertible and infant seats RF. Help!

I have a 11 month old (22 lbs, 31") in a Graco Safeseat which is good until 30 lbs and 32". I am expecting our 2nd child in October and plan on getting a Combi Shuttle 33 to go with the new doube stroller or keeping the Graco, not sure which. At some point, I need a convertible seat for DD 1 and I thought I could do that sooner rather than later depending on if DD 2 will use the Graco or newer Combi infant seat.
I want to keep DD 1 RF as long as possible of course. I guess I am trying to plan ahead to keep space and budget in mind without having to purchase new seats all the time to make them configure in my car. I have a 2007 Hyundai Sante Fe. The Safeseat is behind the passenger seat and touches the back.
I was interested in a convertible being in the middle RF and am considering a Safety 1st Air Protect and most recently the Radian XTSL or 80 (not sure of the big difference in the two). I purchased the Air Protect the other day with a great sale and coupon, but might return since it does not seem to fit properly RF (taking up too much room). I understand that it may not need to recline all the way if my child is not an infant with poor head control. BTW, reclined all the way doesn't work in the middle or behind passenger seat in my car.
I know we will one day have another child and I am thinking I should go with the Radian in order to eventually fit everything back there.
Can anyone shed more light on the subject? I have done tons of research, but still am at a loss.
Should I keep DD1 in the RF infant seat as long as possible, then get the convertible or get one now?
Sorry so long! Too much info in my head now to make a decision on the best convertible seat RF for my car.

You can move to a convertible seat at any time. I have a Mazda CX-7 and I don't think there is much of a size difference between our back seats. I have no problems fitting the Radian, True Fit, and MyRide in my vehicle. All 3 fit both in an outerboard position and in the center. I also don't see why a Complete Air wouldn't fit as well. It fits GREAT in very small vehicles because it is easy to get upright while RF. If you can fit a RF car seat in your vehicle, you can fit most convertible car seats in that same position because they can sit much more upright at 11 months old.

How much room does your DD have above the top of her head in the infant seat? Although the stated height limit for that seat is 32 inches, long torsoed children will outgrow that seat before reaching 32 inches. There are also those short torsoed children that will fit in that infant seat longer than the stated 32 inches. If there is less than an inch of shell above the top of her head, she has outgrown the infant seat and needs a new seat ASAP.

Thanks for the input! I was a bit thrown off when the directions indicated that it needed to be reclined RF, but I see now it can be upright. I'll try it that way as well. I've still got it in my possession currently.
Since I found this site, I've become more impressed with the Radian with the higher weight limit.

cajunqueen said:

Thanks for the input! I was a bit thrown off when the directions indicated that it needed to be reclined RF, but I see now it can be upright. I'll try it that way as well. I've still got it in my possession currently.
Since I found this site, I've become more impressed with the Radian with the higher weight limit.

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Just to clarify, since I didn't to that in my last post, the car seat needs to be in recline mode but can be installed at a more upright angle. Hope this makes sense